@tanstack/virtual-core - npm Package Compare versions

Comparing version 3.15.0 to 3.16.0

dist/cjs/index.cjs

@@ -169,2 +169,3 @@ "use strict";
     this.lanesSettling = false;
+    this.pendingScrollAnchor = null;
     this.scrollRect = null;
@@ -237,2 +238,3 @@ this.scrollOffset = null;
     this.setOptions = (opts2) => {
+      var _a, _b;
       const merged = {
@@ -258,2 +260,5 @@ debug: false,
         lanes: 1,
+        anchorTo: "start",
+        followOnAppend: false,
+        scrollEndThreshold: 1,
         isScrollingResetDelay: 150,
@@ -270,3 +275,32 @@ enabled: true,
       }
+      const prevOptions = this.options;
+      let anchor = null;
+      let followOnAppend = null;
+      if (prevOptions !== void 0 && prevOptions.enabled && merged.enabled && merged.anchorTo === "end" && this.scrollElement !== null) {
+        const prevCount = prevOptions.count;
+        const nextCount = merged.count;
+        const measurements = this.getMeasurements();
+        const prevFirstKey = prevCount > 0 ? ((_a = measurements[0]) == null ? void 0 : _a.key) ?? prevOptions.getItemKey(0) : null;
+        const prevLastKey = prevCount > 0 ? ((_b = measurements[prevCount - 1]) == null ? void 0 : _b.key) ?? prevOptions.getItemKey(prevCount - 1) : null;
+        const didCountChange = nextCount !== prevCount;
+        const didEdgeKeysChange = didCountChange || prevCount > 0 && nextCount > 0 && (merged.getItemKey(0) !== prevFirstKey || merged.getItemKey(nextCount - 1) !== prevLastKey);
+        if (didEdgeKeysChange) {
+          const item = prevCount > 0 ? this.getVirtualItemForOffset(this.getScrollOffset()) ?? measurements[0] : null;
+          if (item) {
+            anchor = [item.key, this.getScrollOffset() - item.start];
+          }
+          const behavior = merged.followOnAppend === true ? "auto" : merged.followOnAppend || null;
+          if (behavior && nextCount > prevCount && this.isAtEnd(prevOptions.scrollEndThreshold) && (prevCount === 0 || merged.getItemKey(nextCount - 1) !== prevLastKey)) {
+            followOnAppend = behavior;
+          }
+        }
+      }
       this.options = merged;
+      if (anchor || followOnAppend) {
+        this.pendingScrollAnchor = [
+          (anchor == null ? void 0 : anchor[0]) ?? null,
+          (anchor == null ? void 0 : anchor[1]) ?? 0,
+          followOnAppend
+        ];
+      }
     };
@@ -403,2 +437,24 @@ this.notify = (sync) => {
       }
+      const anchor = this.pendingScrollAnchor;
+      this.pendingScrollAnchor = null;
+      if (anchor && this.scrollElement && this.options.enabled) {
+        const [key, offset, followOnAppend] = anchor;
+        if (key !== null) {
+          const { count, getItemKey } = this.options;
+          let index = 0;
+          while (index < count && getItemKey(index) !== key) {
+            index++;
+          }
+          const item = index < count ? this.getMeasurements()[index] : void 0;
+          if (item) {
+            const delta = item.start + offset - this.getScrollOffset();
+            if (!utils.approxEqual(delta, 0)) {
+              this.applyScrollAdjustment(delta);
+            }
+          }
+        }
+        if (followOnAppend) {
+          this.scrollToEnd({ behavior: followOnAppend });
+        }
+      }
     };
@@ -729,3 +785,3 @@ this._flushIosDeferredIfReady = () => {
     this.resizeItem = (index, size) => {
-      var _a;
+      var _a, _b;
       if (index < 0 || index >= this.options.count) return;
@@ -750,3 +806,5 @@ let cachedSize;
       if (delta !== 0) {
-        if (((_a = this.scrollState) == null ? void 0 : _a.behavior) !== "smooth" && (this.shouldAdjustScrollPositionOnItemSizeChange !== void 0 ? this.shouldAdjustScrollPositionOnItemSizeChange(
+        const wasAtEnd = this.options.anchorTo === "end" && ((_a = this.scrollState) == null ? void 0 : _a.behavior) !== "smooth" && this.getVirtualDistanceFromEnd() <= this.options.scrollEndThreshold;
+        const prevTotalSize = wasAtEnd ? this.getTotalSize() : 0;
+        const shouldAdjustScroll = ((_b = this.scrollState) == null ? void 0 : _b.behavior) !== "smooth" && (this.shouldAdjustScrollPositionOnItemSizeChange !== void 0 ? this.shouldAdjustScrollPositionOnItemSizeChange(
           // The callback expects a VirtualItem; build one lazily only
@@ -772,15 +830,3 @@ // when the consumer actually supplied a custom predicate.
           itemStart < this.getScrollOffset() + this.scrollAdjustments && this.scrollDirection !== "backward"
-        ))) {
-          if (process.env.NODE_ENV !== "production" && this.options.debug) {
-            console.info("correction", delta);
-          }
-          if (isIOSWebKit() && (this.isScrolling || this._iosTouching || this._iosJustTouchEnded)) {
-            this._iosDeferredAdjustment += delta;
-          } else {
-            this._scrollToOffset(this.getScrollOffset(), {
-              adjustments: this.scrollAdjustments += delta,
-              behavior: void 0
-            });
-          }
-        }
+        ));
         if (this.pendingMin === null || index < this.pendingMin) {
@@ -791,2 +837,7 @@ this.pendingMin = index;
         this.itemSizeCacheVersion++;
+        if (wasAtEnd) {
+          this.applyScrollAdjustment(this.getTotalSize() - prevTotalSize);
+        } else if (shouldAdjustScroll) {
+          this.applyScrollAdjustment(delta);
+        }
         this.notify(false);
@@ -835,2 +886,14 @@ }
     };
+    this.getVirtualDistanceFromEnd = () => {
+      return Math.max(
+        this.getTotalSize() - this.getSize() - this.getScrollOffset(),
+        0
+      );
+    };
+    this.getDistanceFromEnd = () => {
+      return Math.max(this.getMaxScrollOffset() - this.getScrollOffset(), 0);
+    };
+    this.isAtEnd = (threshold = this.options.scrollEndThreshold) => {
+      return this.getDistanceFromEnd() <= threshold;
+    };
     this.getOffsetForAlignment = (toOffset, align, itemSize = 0) => {
@@ -925,2 +988,14 @@ if (!this.scrollElement) return 0;
     };
+    this.scrollToEnd = ({ behavior = "auto" } = {}) => {
+      if (this.options.count > 0) {
+        this.scrollToIndex(this.options.count - 1, {
+          align: "end",
+          behavior
+        });
+        return;
+      }
+      this.scrollToOffset(Math.max(this.getTotalSize() - this.getSize(), 0), {
+        behavior
+      });
+    };
     this.getTotalSize = () => {
@@ -991,2 +1066,16 @@ var _a;
   }
+  applyScrollAdjustment(delta, behavior) {
+    if (delta === 0) return;
+    if (process.env.NODE_ENV !== "production" && this.options.debug) {
+      console.info("correction", delta);
+    }
+    if (isIOSWebKit() && (this.isScrolling || this._iosTouching || this._iosJustTouchEnded)) {
+      this._iosDeferredAdjustment += delta;
+    } else {
+      this._scrollToOffset(this.getScrollOffset(), {
+        adjustments: this.scrollAdjustments += delta,
+        behavior
+      });
+    }
+  }
   scheduleScrollReconcile() {
@@ -993,0 +1082,0 @@ if (!this.targetWindow) {

dist/cjs/index.d.cts

@@ -7,2 +7,4 @@ export declare const _resetIOSDetectionForTests: () => void;
 type ScrollBehavior = 'auto' | 'smooth' | 'instant';
+type ScrollAnchor = 'start' | 'end';
+type FollowOnAppend = boolean | ScrollBehavior;
 export interface ScrollToOptions {
@@ -14,2 +16,3 @@ align?: ScrollAlignment;
 type ScrollToIndexOptions = ScrollToOptions;
+type ScrollToEndOptions = Pick<ScrollToOptions, 'behavior'>;
 export interface Range {
@@ -79,2 +82,5 @@ startIndex: number;
     lanes?: number;
+    anchorTo?: ScrollAnchor;
+    followOnAppend?: FollowOnAppend;
+    scrollEndThreshold?: number;
     isScrollingResetDelay?: number;
@@ -103,2 +109,3 @@ useScrollendEvent?: boolean;
     private lanesSettling;
+    private pendingScrollAnchor;
     scrollRect: Rect | null;
@@ -124,2 +131,3 @@ scrollOffset: number | null;
     private notify;
+    private applyScrollAdjustment;
     private maybeNotify;
@@ -164,2 +172,5 @@ private cleanup;
     private getMaxScrollOffset;
+    private getVirtualDistanceFromEnd;
+    getDistanceFromEnd: () => number;
+    isAtEnd: (threshold?: number) => boolean;
     getOffsetForAlignment: (toOffset: number, align: ScrollAlignment, itemSize?: number) => number;
@@ -170,2 +181,3 @@ getOffsetForIndex: (index: number, align?: ScrollAlignment) => readonly [number, "auto"] | readonly [number, "start" | "center" | "end"] | undefined;
     scrollBy: (delta: number, { behavior }?: ScrollToOffsetOptions) => void;
+    scrollToEnd: ({ behavior }?: ScrollToEndOptions) => void;
     getTotalSize: () => number;
@@ -172,0 +184,0 @@ /**

dist/esm/index.d.ts

@@ -7,2 +7,4 @@ export declare const _resetIOSDetectionForTests: () => void;
 type ScrollBehavior = 'auto' | 'smooth' | 'instant';
+type ScrollAnchor = 'start' | 'end';
+type FollowOnAppend = boolean | ScrollBehavior;
 export interface ScrollToOptions {
@@ -14,2 +16,3 @@ align?: ScrollAlignment;
 type ScrollToIndexOptions = ScrollToOptions;
+type ScrollToEndOptions = Pick<ScrollToOptions, 'behavior'>;
 export interface Range {
@@ -79,2 +82,5 @@ startIndex: number;
     lanes?: number;
+    anchorTo?: ScrollAnchor;
+    followOnAppend?: FollowOnAppend;
+    scrollEndThreshold?: number;
     isScrollingResetDelay?: number;
@@ -103,2 +109,3 @@ useScrollendEvent?: boolean;
     private lanesSettling;
+    private pendingScrollAnchor;
     scrollRect: Rect | null;
@@ -124,2 +131,3 @@ scrollOffset: number | null;
     private notify;
+    private applyScrollAdjustment;
     private maybeNotify;
@@ -164,2 +172,5 @@ private cleanup;
     private getMaxScrollOffset;
+    private getVirtualDistanceFromEnd;
+    getDistanceFromEnd: () => number;
+    isAtEnd: (threshold?: number) => boolean;
     getOffsetForAlignment: (toOffset: number, align: ScrollAlignment, itemSize?: number) => number;
@@ -170,2 +181,3 @@ getOffsetForIndex: (index: number, align?: ScrollAlignment) => readonly [number, "auto"] | readonly [number, "start" | "center" | "end"] | undefined;
     scrollBy: (delta: number, { behavior }?: ScrollToOffsetOptions) => void;
+    scrollToEnd: ({ behavior }?: ScrollToEndOptions) => void;
     getTotalSize: () => number;
@@ -172,0 +184,0 @@ /**

dist/esm/index.js

 import { createLazyMeasurementsView } from "./lazy-measurements.js";
-import { memo, notUndefined, approxEqual, debounce } from "./utils.js";
+import { memo, approxEqual, notUndefined, debounce } from "./utils.js";
 let _isIOSResult;
@@ -167,2 +167,3 @@ const isIOSWebKit = () => {
     this.lanesSettling = false;
+    this.pendingScrollAnchor = null;
     this.scrollRect = null;
@@ -235,2 +236,3 @@ this.scrollOffset = null;
     this.setOptions = (opts2) => {
+      var _a, _b;
       const merged = {
@@ -256,2 +258,5 @@ debug: false,
         lanes: 1,
+        anchorTo: "start",
+        followOnAppend: false,
+        scrollEndThreshold: 1,
         isScrollingResetDelay: 150,
@@ -268,3 +273,32 @@ enabled: true,
       }
+      const prevOptions = this.options;
+      let anchor = null;
+      let followOnAppend = null;
+      if (prevOptions !== void 0 && prevOptions.enabled && merged.enabled && merged.anchorTo === "end" && this.scrollElement !== null) {
+        const prevCount = prevOptions.count;
+        const nextCount = merged.count;
+        const measurements = this.getMeasurements();
+        const prevFirstKey = prevCount > 0 ? ((_a = measurements[0]) == null ? void 0 : _a.key) ?? prevOptions.getItemKey(0) : null;
+        const prevLastKey = prevCount > 0 ? ((_b = measurements[prevCount - 1]) == null ? void 0 : _b.key) ?? prevOptions.getItemKey(prevCount - 1) : null;
+        const didCountChange = nextCount !== prevCount;
+        const didEdgeKeysChange = didCountChange || prevCount > 0 && nextCount > 0 && (merged.getItemKey(0) !== prevFirstKey || merged.getItemKey(nextCount - 1) !== prevLastKey);
+        if (didEdgeKeysChange) {
+          const item = prevCount > 0 ? this.getVirtualItemForOffset(this.getScrollOffset()) ?? measurements[0] : null;
+          if (item) {
+            anchor = [item.key, this.getScrollOffset() - item.start];
+          }
+          const behavior = merged.followOnAppend === true ? "auto" : merged.followOnAppend || null;
+          if (behavior && nextCount > prevCount && this.isAtEnd(prevOptions.scrollEndThreshold) && (prevCount === 0 || merged.getItemKey(nextCount - 1) !== prevLastKey)) {
+            followOnAppend = behavior;
+          }
+        }
+      }
       this.options = merged;
+      if (anchor || followOnAppend) {
+        this.pendingScrollAnchor = [
+          (anchor == null ? void 0 : anchor[0]) ?? null,
+          (anchor == null ? void 0 : anchor[1]) ?? 0,
+          followOnAppend
+        ];
+      }
     };
@@ -401,2 +435,24 @@ this.notify = (sync) => {
       }
+      const anchor = this.pendingScrollAnchor;
+      this.pendingScrollAnchor = null;
+      if (anchor && this.scrollElement && this.options.enabled) {
+        const [key, offset, followOnAppend] = anchor;
+        if (key !== null) {
+          const { count, getItemKey } = this.options;
+          let index = 0;
+          while (index < count && getItemKey(index) !== key) {
+            index++;
+          }
+          const item = index < count ? this.getMeasurements()[index] : void 0;
+          if (item) {
+            const delta = item.start + offset - this.getScrollOffset();
+            if (!approxEqual(delta, 0)) {
+              this.applyScrollAdjustment(delta);
+            }
+          }
+        }
+        if (followOnAppend) {
+          this.scrollToEnd({ behavior: followOnAppend });
+        }
+      }
     };
@@ -727,3 +783,3 @@ this._flushIosDeferredIfReady = () => {
     this.resizeItem = (index, size) => {
-      var _a;
+      var _a, _b;
       if (index < 0 || index >= this.options.count) return;
@@ -748,3 +804,5 @@ let cachedSize;
       if (delta !== 0) {
-        if (((_a = this.scrollState) == null ? void 0 : _a.behavior) !== "smooth" && (this.shouldAdjustScrollPositionOnItemSizeChange !== void 0 ? this.shouldAdjustScrollPositionOnItemSizeChange(
+        const wasAtEnd = this.options.anchorTo === "end" && ((_a = this.scrollState) == null ? void 0 : _a.behavior) !== "smooth" && this.getVirtualDistanceFromEnd() <= this.options.scrollEndThreshold;
+        const prevTotalSize = wasAtEnd ? this.getTotalSize() : 0;
+        const shouldAdjustScroll = ((_b = this.scrollState) == null ? void 0 : _b.behavior) !== "smooth" && (this.shouldAdjustScrollPositionOnItemSizeChange !== void 0 ? this.shouldAdjustScrollPositionOnItemSizeChange(
           // The callback expects a VirtualItem; build one lazily only
@@ -770,15 +828,3 @@ // when the consumer actually supplied a custom predicate.
           itemStart < this.getScrollOffset() + this.scrollAdjustments && this.scrollDirection !== "backward"
-        ))) {
-          if (process.env.NODE_ENV !== "production" && this.options.debug) {
-            console.info("correction", delta);
-          }
-          if (isIOSWebKit() && (this.isScrolling || this._iosTouching || this._iosJustTouchEnded)) {
-            this._iosDeferredAdjustment += delta;
-          } else {
-            this._scrollToOffset(this.getScrollOffset(), {
-              adjustments: this.scrollAdjustments += delta,
-              behavior: void 0
-            });
-          }
-        }
+        ));
         if (this.pendingMin === null || index < this.pendingMin) {
@@ -789,2 +835,7 @@ this.pendingMin = index;
         this.itemSizeCacheVersion++;
+        if (wasAtEnd) {
+          this.applyScrollAdjustment(this.getTotalSize() - prevTotalSize);
+        } else if (shouldAdjustScroll) {
+          this.applyScrollAdjustment(delta);
+        }
         this.notify(false);
@@ -833,2 +884,14 @@ }
     };
+    this.getVirtualDistanceFromEnd = () => {
+      return Math.max(
+        this.getTotalSize() - this.getSize() - this.getScrollOffset(),
+        0
+      );
+    };
+    this.getDistanceFromEnd = () => {
+      return Math.max(this.getMaxScrollOffset() - this.getScrollOffset(), 0);
+    };
+    this.isAtEnd = (threshold = this.options.scrollEndThreshold) => {
+      return this.getDistanceFromEnd() <= threshold;
+    };
     this.getOffsetForAlignment = (toOffset, align, itemSize = 0) => {
@@ -923,2 +986,14 @@ if (!this.scrollElement) return 0;
     };
+    this.scrollToEnd = ({ behavior = "auto" } = {}) => {
+      if (this.options.count > 0) {
+        this.scrollToIndex(this.options.count - 1, {
+          align: "end",
+          behavior
+        });
+        return;
+      }
+      this.scrollToOffset(Math.max(this.getTotalSize() - this.getSize(), 0), {
+        behavior
+      });
+    };
     this.getTotalSize = () => {
@@ -989,2 +1064,16 @@ var _a;
   }
+  applyScrollAdjustment(delta, behavior) {
+    if (delta === 0) return;
+    if (process.env.NODE_ENV !== "production" && this.options.debug) {
+      console.info("correction", delta);
+    }
+    if (isIOSWebKit() && (this.isScrolling || this._iosTouching || this._iosJustTouchEnded)) {
+      this._iosDeferredAdjustment += delta;
+    } else {
+      this._scrollToOffset(this.getScrollOffset(), {
+        adjustments: this.scrollAdjustments += delta,
+        behavior
+      });
+    }
+  }
   scheduleScrollReconcile() {
@@ -991,0 +1080,0 @@ if (!this.targetWindow) {

package.json

 {
   "name": "@tanstack/virtual-core",
-  "version": "3.15.0",
+  "version": "3.16.0",
   "description": "Headless UI for virtualizing scrollable elements in TS/JS + Frameworks",
@@ -5,0 +5,0 @@ "author": "Tanner Linsley",

src/index.ts

@@ -36,2 +36,6 @@ import { createLazyMeasurementsView } from './lazy-measurements'
 
+type ScrollAnchor = 'start' | 'end'
+
+type FollowOnAppend = boolean | ScrollBehavior
+
 export interface ScrollToOptions {
@@ -46,2 +50,4 @@ align?: ScrollAlignment
 
+type ScrollToEndOptions = Pick<ScrollToOptions, 'behavior'>
+
 export interface Range {
@@ -333,2 +339,5 @@ startIndex: number
   lanes?: number
+  anchorTo?: ScrollAnchor
+  followOnAppend?: FollowOnAppend
+  scrollEndThreshold?: number
   isScrollingResetDelay?: number
@@ -358,2 +367,8 @@ useScrollendEvent?: boolean
 
+type PendingScrollAnchor = [
+  key: Key | null,
+  offset: number,
+  followOnAppend: ScrollBehavior | null,
+]
+
 export class Virtualizer<
@@ -381,2 +396,3 @@ TScrollElement extends Element | Window,
   private lanesSettling = false
+  private pendingScrollAnchor: PendingScrollAnchor | null = null
   scrollRect: Rect | null = null
@@ -506,2 +522,5 @@ scrollOffset: number | null = null
       lanes: 1,
+      anchorTo: 'start',
+      followOnAppend: false,
+      scrollEndThreshold: 1,
       isScrollingResetDelay: 150,
@@ -520,3 +539,71 @@ enabled: true,
 
+    const prevOptions = this.options as
+      | Required<VirtualizerOptions<TScrollElement, TItemElement>>
+      | undefined
+    let anchor: [Key, number] | null = null
+    let followOnAppend: ScrollBehavior | null = null
+
+    if (
+      prevOptions !== undefined &&
+      prevOptions.enabled &&
+      merged.enabled &&
+      merged.anchorTo === 'end' &&
+      this.scrollElement !== null
+    ) {
+      const prevCount = prevOptions.count
+      const nextCount = merged.count
+      const measurements = this.getMeasurements()
+      const prevFirstKey =
+        prevCount > 0
+          ? (measurements[0]?.key ?? prevOptions.getItemKey(0))
+          : null
+      const prevLastKey =
+        prevCount > 0
+          ? (measurements[prevCount - 1]?.key ??
+            prevOptions.getItemKey(prevCount - 1))
+          : null
+      const didCountChange = nextCount !== prevCount
+      const didEdgeKeysChange =
+        didCountChange ||
+        (prevCount > 0 &&
+          nextCount > 0 &&
+          (merged.getItemKey(0) !== prevFirstKey ||
+            merged.getItemKey(nextCount - 1) !== prevLastKey))
+
+      if (didEdgeKeysChange) {
+        const item =
+          prevCount > 0
+            ? (this.getVirtualItemForOffset(this.getScrollOffset()) ??
+              measurements[0])
+            : null
+
+        if (item) {
+          anchor = [item.key, this.getScrollOffset() - item.start]
+        }
+
+        const behavior =
+          merged.followOnAppend === true
+            ? 'auto'
+            : merged.followOnAppend || null
+
+        if (
+          behavior &&
+          nextCount > prevCount &&
+          this.isAtEnd(prevOptions.scrollEndThreshold) &&
+          (prevCount === 0 || merged.getItemKey(nextCount - 1) !== prevLastKey)
+        ) {
+          followOnAppend = behavior
+        }
+      }
+    }
+
     this.options = merged
+
+    if (anchor || followOnAppend) {
+      this.pendingScrollAnchor = [
+        anchor?.[0] ?? null,
+        anchor?.[1] ?? 0,
+        followOnAppend,
+      ]
+    }
   }
@@ -528,2 +615,22 @@
 
+  private applyScrollAdjustment(delta: number, behavior?: ScrollBehavior) {
+    if (delta === 0) return
+
+    if (process.env.NODE_ENV !== 'production' && this.options.debug) {
+      console.info('correction', delta)
+    }
+
+    if (
+      isIOSWebKit() &&
+      (this.isScrolling || this._iosTouching || this._iosJustTouchEnded)
+    ) {
+      this._iosDeferredAdjustment += delta
+    } else {
+      this._scrollToOffset(this.getScrollOffset(), {
+        adjustments: (this.scrollAdjustments += delta),
+        behavior,
+      })
+    }
+  }
+
   private maybeNotify = memo(
@@ -697,2 +804,30 @@ () => {
     }
+
+    const anchor = this.pendingScrollAnchor
+    this.pendingScrollAnchor = null
+
+    if (anchor && this.scrollElement && this.options.enabled) {
+      const [key, offset, followOnAppend] = anchor
+
+      if (key !== null) {
+        const { count, getItemKey } = this.options
+        let index = 0
+        while (index < count && getItemKey(index) !== key) {
+          index++
+        }
+
+        const item = index < count ? this.getMeasurements()[index] : undefined
+        if (item) {
+          const delta = item.start + offset - this.getScrollOffset()
+
+          if (!approxEqual(delta, 0)) {
+            this.applyScrollAdjustment(delta)
+          }
+        }
+      }
+
+      if (followOnAppend) {
+        this.scrollToEnd({ behavior: followOnAppend })
+      }
+    }
   }
@@ -1296,4 +1431,9 @@
     if (delta !== 0) {
-      if (
+      const wasAtEnd =
+        this.options.anchorTo === 'end' &&
         this.scrollState?.behavior !== 'smooth' &&
+        this.getVirtualDistanceFromEnd() <= this.options.scrollEndThreshold
+      const prevTotalSize = wasAtEnd ? this.getTotalSize() : 0
+      const shouldAdjustScroll =
+        this.scrollState?.behavior !== 'smooth' &&
         (this.shouldAdjustScrollPositionOnItemSizeChange !== undefined
@@ -1322,22 +1462,2 @@ ? this.shouldAdjustScrollPositionOnItemSizeChange(
             this.scrollDirection !== 'backward')
-      ) {
-        if (process.env.NODE_ENV !== 'production' && this.options.debug) {
-          console.info('correction', delta)
-        }
-        // On iOS WebKit, writing scrollTop while a finger is on screen or
-        // momentum-scroll is running cancels the in-flight scroll. Defer
-        // the adjustment until iOS is fully settled — flushed by either
-        // the scroll callback or the touchend grace-timer.
-        if (
-          isIOSWebKit() &&
-          (this.isScrolling || this._iosTouching || this._iosJustTouchEnded)
-        ) {
-          this._iosDeferredAdjustment += delta
-        } else {
-          this._scrollToOffset(this.getScrollOffset(), {
-            adjustments: (this.scrollAdjustments += delta),
-            behavior: undefined,
-          })
-        }
-      }
 
@@ -1350,2 +1470,8 @@ if (this.pendingMin === null || index < this.pendingMin) {
 
+      if (wasAtEnd) {
+        this.applyScrollAdjustment(this.getTotalSize() - prevTotalSize)
+      } else if (shouldAdjustScroll) {
+        this.applyScrollAdjustment(delta)
+      }
+
       this.notify(false)
@@ -1413,2 +1539,17 @@ }
 
+  private getVirtualDistanceFromEnd = () => {
+    return Math.max(
+      this.getTotalSize() - this.getSize() - this.getScrollOffset(),
+      0,
+    )
+  }
+
+  getDistanceFromEnd = () => {
+    return Math.max(this.getMaxScrollOffset() - this.getScrollOffset(), 0)
+  }
+
+  isAtEnd = (threshold = this.options.scrollEndThreshold) => {
+    return this.getDistanceFromEnd() <= threshold
+  }
+
   getOffsetForAlignment = (
@@ -1549,2 +1690,16 @@ toOffset: number,
 
+  scrollToEnd = ({ behavior = 'auto' }: ScrollToEndOptions = {}) => {
+    if (this.options.count > 0) {
+      this.scrollToIndex(this.options.count - 1, {
+        align: 'end',
+        behavior,
+      })
+      return
+    }
+
+    this.scrollToOffset(Math.max(this.getTotalSize() - this.getSize(), 0), {
+      behavior,
+    })
+  }
+
   getTotalSize = () => {
@@ -1551,0 +1706,0 @@ const measurements = this.getMeasurements()

New alerts

Environment variable access

Supply chain risk

Package accesses environment variables, which may be a sign of credential stuffing or data theft.

Found 1 instance in 1 package

Long strings

Supply chain risk

Contains long string literals, which may be a sign of obfuscated or packed code.

Found 1 instance in 1 package

Fixed alerts

Environment variable access

Supply chain risk

Package accesses environment variables, which may be a sign of credential stuffing or data theft.

Found 1 instance in 1 package

Long strings

Supply chain risk

Contains long string literals, which may be a sign of obfuscated or packed code.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

363170

7.84%

Lines of code

4607

7.44%

Worsened metrics

Number of low supply chain risk alerts

30

3.45%

No dependency changes